At the onset of the War of the Second Coalition in 1799, when the armies of the Danube and Helvetia were formed, he was assigned to the Army of the Danube under command of Jean Baptiste Jourdan. His 10th Regiment was part of Laurent de Gouvion Saint-Cyr's III. Division, and held the far left flank at the Battle of Ostrach, 21 March 1799, in southwestern Germany. Although he was wounded on 14 August 1799 in Switzerland, he participated in the Second Battle of Zurich in which his 10th Chasseurs à Cheval routed a division of Russians, a decisive moment in the French victory. Ordener was promoted to colonel of the regiment in 1801 and on 29 August 1803, he was promoted to general of brigade. Duke d'Enghien affair On Napoleon's orders, Ordener entered into the most controversial action of his career, leading a raid into the sovereign Grand Duchy of Baden to arrest Louis Antoine, Duke of Enghien, in 1804. Napoleon's orders were specific: Ordener and Armand Augustin Caulaincourt were to take 300 dragoons into the duchy, surround the village of Ettenheim, where the Duke lived, arrest the Duke and Charles Francois Dumouriez, who Napoleon believed was present, and bring both of the men back to France. Ordener and Caulaincourt were instructed also to take their own provisions and to inflict neither harm nor damage on any of the duchy's inhabitants or their property. In the night of 14–15 March, the dragoons crossed the Rhine and surrounded the Duke's lodgings. Dumouriez was not there, nor had he been, but they kidnapped the Duke and took him away to France. Within a few days, the Duke was spirited into the Chateau de Vincennes, on the outskirts of Paris. There he was tried for treason and executed immediately after the verdict. This action, which involved the invasion of a sovereign state, the kidnapping of a duke and a sham trial for treason followed by the man's immediate execution, had political and diplomatic repercussions throughout Europe. Campaigns in Austria and Prussia In 1805, Ordener participated in the campaign against Austria as commander of a regiment of horse grenadiers of the Imperial Guard. At the Battle of Austerlitz, he led a decisive and energetic charge. He executed this, upon order of Napoleon, with impetuosity; this was the charge that pushed the Russians onto the ice and during which, French sources maintain, 40,000 Russians drowned